Table 1 Activities of different CyaA mutants on black lipid membranes.

From: The conserved tyrosine residue 940 plays a key structural role in membrane interaction of Bordetella adenylate cyclase toxin

 

Most frequent single pore conductance (pS)a

Pore lifetime Ï„ (s)b

Overall membrane activityc

CyaA

8.7 ± 1.8

1.64 ± 0.14

+++

CyaA-A609P

6.4 ± 1.4

1.61 ± 0.42

+

CyaA-A616P

9.6 ± 2.2

1.64 ± 0.23

++

CyaA-E622P

5.4 ± 1.3

1.63 ± 0.51

+/−

CyaA-A680P

8.8 ± 1.7

0.88 ± 0.09

++

CyaA-A687P

6.1 ± 1.7

0.74 ± 0.10

+

CyaA-V695P

6.9 ± 1.8

0.86 ± 0.37

++

CyaA-Y940F

7.3 ± 1.6

2.01 ± 0.45

+++

CyaA-Y940A

8.0 ± 1.6

1.40 ± 0.18

+/−

CyaA-Y940P

6.3 ± 1.3

1.75 ± 0.76

+/−

  1. aSingle-pore conductance of intact CyaA and its mutant variants (1 nM) was determined in 150 mM KCl, 10 mM Tris-HCl and 2 mM CaCl2 (pH 7.4) at 25 °C and membrane potential −50 mV. The average values ± S.D. (half width at half maximum) are shown.
  2. bFor lifetime determination, the kernel density estimation of dwell times (of ~700 individual pore openings) was fitted with a double-exponential function. The error estimates of lifetimes were obtained by bootstrap analysis. We show only lifetime > 500 ms.
  3. cThe overall membrane activity was detected after 5 minutes incubation of the membranes with individual proteins at 1 nM concentration. The number of plus signs refers to the overall conductance of the membrane/cm2 induced by the various CyaA proteins under these conditions in asolectin membranes and reflects the conductance (size), the lifetime, and the specific frequency of formation of pores by the various CyaA constructs.
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